It sounds to me like you have to move your derailleur cage just a skosh to the right. That will require a cable tension increase and/or a limit screw adjustment. Either way, don't overdo it. You will only need about 1/8 turn. Too much and you'll find yourself throwing the chain to the outside.
Leave the shifter alone for a minute. Try to move the cage by just pulling on the bare shift cable. If that won't move the cage, back out your high limit screw about 1/8 turn. If that fixes it, (my guess) you're done. If it doesn't, try increasing your cable tension 1/8 turn.